Abstract
We report on the real-time in situ detection of SF6 in a plasma etching reactor with μTorr sensitivity using a tunable diode laser absorption spectrometer. The spectrometer employs combined wavelength and frequency modulation of the laser diode, an approach which allows for sensitive, interference fringe-free detection of the SF6. The dual modulation scheme also provides a feedback signal which enables the laser to be frequency locked to the absorption line.
Original language | English |
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Pages (from-to) | 1035-1037 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 63 |
Issue number | 8 |
DOIs | |
State | Published - 1993 |